feat: add automatic update functionality for Electron app

Closes #613

- Add electron-updater for Windows NSIS and Linux AppImage auto-update
- macOS and Linux DEB fall back to GitHub API check with download link
- Add "Check for Updates" menu item with i18n (en, zh, ja, zh-Hant)
- Fix Windows CI workflow to publish correct latest.yml after code signing
- Add update toast notifications in renderer via sonner

components/chat-panel.tsx

@@ -25,6 +25,7 @@ import Image from "@/components/image-with-basepath"
 import { ModelConfigDialog } from "@/components/model-config-dialog"
 import { SettingsDialog } from "@/components/settings-dialog"
 import { useDiagram } from "@/contexts/diagram-context"
+import { useAutoUpdate } from "@/hooks/use-auto-update"
 import { useDiagramToolHandlers } from "@/hooks/use-diagram-tool-handlers"
 import { useDictionary } from "@/hooks/use-dictionary"
 import { getSelectedAIConfig, useModelConfig } from "@/hooks/use-model-config"
@@ -1253,10 +1254,22 @@ export default function ChatPanel({
         sendChatMessage(newParts, savedXml, previousXml, sessionId)
     }
 
+    // Auto-update listener (must be before early return so it's always active)
+    useAutoUpdate()
+
     // Collapsed view (desktop only)
     if (!isVisible && !isMobile) {
         return (
             <div className="h-full flex flex-col items-center pt-4 bg-card border border-border/30 rounded-xl">
+                <Toaster
+                    position="bottom-left"
+                    richColors
+                    expand
+                    toastOptions={{
+                        style: { maxWidth: "480px" },
+                        duration: 2000,
+                    }}
+                />
                 <ButtonWithTooltip
                     tooltipContent={dict.nav.showPanel}
                     variant="ghost"

components/update-toast.tsx

@@ -0,0 +1,124 @@
+"use client"
+
+import type React from "react"
+
+interface UpdateToastAvailableProps {
+    variant: "download"
+    version: string
+    onDownload: () => void
+    onDismiss: () => void
+}
+
+interface UpdateToastManualProps {
+    variant: "manual"
+    version: string
+    url: string
+    onDismiss: () => void
+}
+
+interface UpdateToastDownloadingProps {
+    variant: "downloading"
+    percent: number
+    onDismiss: () => void
+}
+
+type UpdateToastProps =
+    | UpdateToastAvailableProps
+    | UpdateToastManualProps
+    | UpdateToastDownloadingProps
+
+export function UpdateToast(props: UpdateToastProps) {
+    const { variant, onDismiss } = props
+
+    const handleKeyDown = (e: React.KeyboardEvent) => {
+        if (e.key === "Escape") {
+            e.preventDefault()
+            onDismiss()
+        }
+    }
+
+    return (
+        <div
+            role="alert"
+            aria-live="polite"
+            tabIndex={0}
+            onKeyDown={handleKeyDown}
+            className="flex items-center gap-3 bg-card border border-border/50 px-4 py-3 rounded-xl shadow-sm"
+        >
+            <div className="flex items-center justify-center w-8 h-8 rounded-full bg-primary/10 flex-shrink-0">
+                <svg
+                    className="w-4 h-4 text-primary"
+                    viewBox="0 0 24 24"
+                    fill="none"
+                    stroke="currentColor"
+                    strokeWidth="2"
+                    strokeLinecap="round"
+                    strokeLinejoin="round"
+                    aria-hidden="true"
+                >
+                    <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4" />
+                    <polyline points="7 10 12 15 17 10" />
+                    <line x1="12" y1="15" x2="12" y2="3" />
+                </svg>
+            </div>
+
+            <div className="flex-1 min-w-0">
+                {variant === "downloading" ? (
+                    <span className="text-sm text-foreground">
+                        Downloading update... {Math.round(props.percent)}%
+                    </span>
+                ) : (
+                    <span className="text-sm text-foreground">
+                        Version {props.version} is available
+                    </span>
+                )}
+            </div>
+
+            {variant === "download" && (
+                <button
+                    type="button"
+                    onClick={(e) => {
+                        e.stopPropagation()
+                        props.onDownload()
+                    }}
+                    className="text-xs font-medium px-3 py-1.5 rounded-lg bg-primary text-primary-foreground hover:bg-primary/90 transition-colors flex-shrink-0"
+                >
+                    Download
+                </button>
+            )}
+
+            {variant === "manual" && (
+                <button
+                    type="button"
+                    onClick={(e) => {
+                        e.stopPropagation()
+                        window.open(props.url, "_blank")
+                    }}
+                    className="text-xs font-medium px-3 py-1.5 rounded-lg bg-primary text-primary-foreground hover:bg-primary/90 transition-colors flex-shrink-0"
+                >
+                    Download
+                </button>
+            )}
+
+            <button
+                type="button"
+                onClick={onDismiss}
+                className="text-muted-foreground hover:text-foreground transition-colors flex-shrink-0"
+                aria-label="Dismiss"
+            >
+                <svg
+                    className="w-4 h-4"
+                    viewBox="0 0 20 20"
+                    fill="currentColor"
+                    aria-hidden="true"
+                >
+                    <path
+                        fillRule="evenodd"
+                        d="M4.293 4.293a1 1 0 011.414 0L10 8.586l4.293-4.293a1 1 0 111.414 1.414L11.414 10l4.293 4.293a1 1 0 01-1.414 1.414L10 11.414l-4.293 4.293a1 1 0 01-1.414-1.414L8.586 10 4.293 5.707a1 1 0 010-1.414z"
+                        clipRule="evenodd"
+                    />
+                </svg>
+            </button>
+        </div>
+    )
+}